Backstack - Optional features

Features can be independently offered, providing additional account-level options beyond the current version functionality. Use optional features for offering unique functionality that might not be suitable for all accounts in the version schema.

Images

When defining version functionality, features can be designated as optional. If a feature is offered optionally, the account needs to subscribe to the feature to access its functionality.

Optional feature constraints are computed in the compiled session environment, and access is granted as a standard feature, resulting in no variations in codebase logic.

// pseudocode

// The version has the widget feature included.

if(hasAccess('widgets:c'))
  <button>Create Widget</button>
  
// The version has the widget feature as an option. (No difference in logic.)

if(hasAccess('widgets:c'))
  <button>Create Widget</button>

Account settings

The current account optional feature subscriptions are listed in the session object.

// session object
{
  ...
  "account": {
    "optional_features": [
      "payments",
      ...
    ]
    ...
  },
  ...
}

Available optional features

The optional features available for the current account are defined in the application schema optional_features.distribution[session.account.version_id] array.

// app schema
{
  ...
  "optional_features": {
    "distribution": {
      "ver_1234567890": [
        "payments",
        ...
      ],
      ...
    },
    "list": {
      "account-users": {
        "title": "Account user management",
        "description": "Manage users and RBAC distribution." 
      }
      ...
    }
  },
  ...
}

Parameter	Type	Description
`optional_features.distribution`	array	Keys are version ids and values are optional feature IDs.
`optional_features.distribution[version_id]`	array	Optional feature IDs available for the version ID.
`optional_features.list`	array	Keys are feature IDs and values are the features data.
`optional_features.list[feature_id].title`	string	The title of the feature.
`optional_features.list[feature_id].description`	string	The features description.

Toggling optional features activation

If the accounts version has optional features available, you'll want to offer methods for activating/deactivating them on your page.

// extracting app schema vaues  for creating an optional features list

optional_features.distribution[session.account.version_id].map((id) => {
  console.log({
    "id": id,
    "title": optional_features.list[id].title,
    "description": optional_features.list[id].description,
    "active": session.account.optional_features.contains(id)
  });
});

Then post the selected feature id to the API to toggle its active status.

Request

POST /v1/account/optional-features/:id

Response

// latest optional feature history record
{
  "id": "afh_1234567890",
  "account_id": "acc_1234567890",
  "feature_id": "payments",
  "timestamp": 1703705293,
  "active": true
}

Monetizing optional features

Invoice items are automatically generated when any of the following fees are implemented.

Fee	Description	Implementation
Version fee	Collect a fee for any version of the application functionality.	Implement in each `domain.version`.
User fee	Collect a fee for each account user.	Implement in each `domain.version`.
Optional feature fee	Collect a fee for any feature designated as `optional`.	Implement in each `domain.version.features`.

See invoicing-accounts for additional information.